1. How does the card stand on its own? Is it good, bad, or has potential?
It is possible for Luxray GL Lv.X to be good on its own. Just look at the deck, Luxbox, and you can see why. Luxray acts like the soul attacker, and it'll use lots of SP support (and others like Uxies and Azelfs) to aid it in its process to take down the opponent. Thus, this shows Luxray can be good on its own. Right now, however, many are not doing this and are bringing another attacker along with Luxray. A good example is Luxchomp. Luxray GL Lv.X is an attacker that is used, but there's also Garchomp C Lv.X that is also attacking a lot. Either way, on its own or not, Luxray is a great card and has potential.
2. What popular metagame decks is it used in?
There are lots of SP decks that will use Luxray. Luxchomp is currently the one that shines with its Luxray usage. Blazeray, Dialga/Garchomp, and Luxbox are other decks that will use it a lot. There have been times Luxray has been played in regular decks too. Look at Speedrill and you'll see what I mean. It isn't an attacker here, but a tech in order to bring out a desired Pokemon to be KOed. Speedrill, Jumpluff, and Gyarados are namely the decks that are well-known for using Luxray as a tech, not an attacker compared to SP decks. Indeed, Luxray GL Lv.X is just one popular card in this metagame.
3. What comboes can you use this card with? How so?
As mentioned, we know Luxray is one beastly attacker, but it is a great tech too. How? Well, it's quite simple? We'll take Gyarados as a good example. Your opponent has a Claydol on the bench. You have a fully ready to attack Gyarados on the bench, and you have a regular Luxray GL as your active. You think, "How do I get this Claydol?" You look at your hand, and you see Luxray GL Lv.X there. You play it onto your active, use Bright Look on their Claydol, and then you retreat, pull out Gyarados, and then you KO it. That's a way I can use it. Its basically using it like a Gust of Wind. Use Luxray's Bright Look to have your main hitter KO something you want KOed.
4. Give it a rating, and explain why you have given it that rating.
Overall, I would give it a 5/5 for the modified. This card is just one insane card. It brings back Gust of Wind through a Poke-Power, and it can attack with it too, so its just one killer attacker. At the same time, Luxray has been used as a tech because of its power in order to have your main hitters take something down that you want KOed. This card is just the best SP out there.
5. How's the artwork?
I just love it. It really shows Luxray's great power. The artwork looks almost like its going to jump on you. Indeed, Mitsuhiro Arita did quite a nice job making the Luxray GL Lv.X artwork.